Is OTR Diagnostics right for you? Take the quiz

These 5 quick checks ensure that you are catching the issues early on so that the repair does not get any worse and cause unexpected breakdowns or repairs.

We always want to be working towards preventative maintenance to extend the longevity of your truck's life, so let's get into it. 

1. Drive Belt Condition

Drive belts need to be checked periodically to ensure they are in good working condition.

The typical drive belt should be replaced every 1-½ year to 2 years depending on the condition.

The drive belt can be worn a few different ways:

  • Normal drive wear that the components (A/C compressor/Alternator/fuel pump) put on the belt
  • Weather worn belt, which includes cracking and belt squeaking
  • Belt has too much free play

The specification for the belt should have no more than ¾ inch free play measured in the middle of the belt.

2. Transmission Oil Level

Making sure you periodically check the transmission oil level is critical.

Common issues include:

  • Bolt/sensor fluid leaks
  • Transmission oil cooler
  • Transmission rear yoke seal
  • Transmission case leaking
  • Improper lubrication.
    The transmission needs to have the proper lubrication to ensure that the components are properly lubed. The oil helps reduce the operating temperature inside the transmission.

Measure your fluid level. Here's how: 

  • Remove the side plug on your transmission using a ½in ratchet.
  • Insert your finger in the transmission and you should feel the transmission oil on the bottom side of the hole. If you do not feel any oil, then you must add oil until the oil is leaking out the side.

    Synthetic 50 WT transmission oil is usually recommended for Volvo trucks.

3. Differential Fluid Level

The most common issue with low differential fluid leak is that the wheel seal has been blown out and is causing the oil to leak out of the wheel end. The wheel seal separates the differential oil that is inside the wheel bearing and the hub assembly. When the wheel seal fails you will notice oil on your brake shoes and oil on the inside part of your tire. The ring and pinion gears inside the differential need to have the proper oil to ensure the rear end does not fail prematurely.

Measure the fluid level. Here's how: 

  • Remove the plug located in the middle of the differential. Tool: ½ ratchet
  • Remove the magnetic plug and make sure you feel oil on the bottom side of the hole.
  • Inspect the magnetic plug for any obvious sign of heavy metal in the oil. If you find any abnormality replace differential oil and inspect further.

    Synthetic 75w-90 for differential oil is usually recommended for Volvo trucks.

4. Coolant Level

Checking your coolant level at the expansion tank is a good habit to create.

You can be sure to find a coolant leak or any other defects if you periodically check the system.

If the cooling system is unable to draw coolant back from the expansion tank you could easily end up with an empty radiator or worst of all an overheated engine.

Common issues

  • Cracked radiator
  • EGR cooler leaking internally 
  • Coolant hose leaking 
  • Expansion tank leaking
  • Transmission cooler
  • Air compressor head gasket has blown
  • Injector cups leaking

    *****Please check the level in the expansion tank only when the engine is cold to avoid being scalded by hot coolant.

We recommend your coolant is replaced every 300,000-500,000 mile intervals to ensure the proper pH levels in your system.

5. Brake Adjustment

The brake system on your truck is the most important item that should not be overlooked.

If these are not in correct working order and properly adjusted the best-designed air brake system will not safely stop the truck.

The reality is that brake failures are almost never caused by an air system failure, but by neglecting maintenance.

The driver may be held responsible if the brakes are incorrectly adjusted or not working properly.

The most common method for checking your slack adjusters for proper adjustment is the pry method of free stroke measurement.

To begin, make sure air pressure is over 100psi in both tanks. Here's how: 

  • Make sure you wheel chock the front and rear tire and release the parking brake
  • Make a mark on the pushrod where it exits the brake chamber
  • Pull the pushrod out from the brake chamber, using a tool for leverage
  • Measure the distance between the chalk mark and the face of the brake chamber – ½ to ¾ of an inch of free stroke is a good range.
    *If this distance is more than ¾ of an inch, the brakes need adjustment.

Common causes of brake failure:

  • Over-adjustment
  • Inaccurate adjustment causing an overheat condition
  • Cracked brake shoes
  • Parking brake not holding vehicle (spring broken)
  • Cracked air hose causing loss of air pressure
  • Brake valve not working properly

Preventative maintenance is important when trying to maintain the longevity of your truck's life and to prevent unnecessary downtime.

We hope these 5 tips come in handy for you!  

Until next time 👋
Stay safe & be blessed.